Do 3-D printers pose a public safety risk?

The technology makes it easy to make such things as illegal weapons, but making them well is a much more difficult proposition

3-D printing is a relatively new technology that holds great promise for the fabrication of everything from human organ replacements to precision machine parts.

Some people are wary of the new machines because they can just as easily make patented designs, and especially gun parts. Just how much of a threat do these machines offer to the public safety?

A 3-D printer works on a principle similar to an inkjet printer. With inkjets, a spray nozzle deposits tiny dots of ink on paper. Between the spread of the ink into the paper and the closeness and size of the dots, the result can be photograph quality.

Instead of ink, 3-D printers use reservoirs of finely divided material that is usually heated until it’s in a liquid (or near-liquid) state, then sprayed onto a surface.

The material is typically some type of plastic, but some metals are compatible with the 3-D printing process. The drops of material harden on contact and stick to the material underneath it.

By depositing incredibly thin layers of the sprayed material, one on top of the other, and permitting the print head to move in three planes, a 3-D object is formed.

3-D printers are capable of tremendous precision and can produce objects that would be nearly impossible to manufacture with conventional methods. A designer produces the object in a 3-D design program like the open-source SketchUp, saves the finished design to a file, and sends it to a 3-D printer in his office or on the other side of the world.

The 3-D printer makes a perfect replica of the object in the plan file. It’s the closest thing to a Star Trek replicator we are likely to see in our lifetimes. Current models start at around $900, although prices of $1500-$2500 are more common. These aren’t casual purchases for most of us, but are certainly within the reach of a serious tinkerer.

Because not all materials have been adapted for use in 3-D printers, the choice of composition materials for 3-D printers is limited. Most use plastics, a few can work with certain types of metal powder, and those in bioengineering labs often use material that mimics human or animal tissue.

One suggested application that may see reality soon is the production of while-you-wait dentures and dental crowns.

Current technology is to make a mold of the desired shape, then send the mold to a dental lab where the denture is cast in porcelain or metal, and detailed by a technician. The process usually requires a couple of weeks.

With a 3-D printer capable of working with a porcelain-like plastic, the dentist could take a multi-angle photo of the tooth to be replaced, send the image file to his printer, and have the replacement installed in the same visit. This would be especially valuable for military dental clinics and those in remote locations. You could carry a complete dental lab in a box.

As with every other good thing on the earth, someone always finds a way to use it for a nefarious purpose. Most semi-auto firearms are easily converted to full-auto with the replacement of one or more small metal parts, which any capable machinist can produce.

What stops most capable machinists from making these is a federal prohibition on manufacture, possession, or sale of the parts, punishable as a felony.

Design specs for the parts have been available on the internet and sold at gun shows for years, and some people have managed to produce functional samples in garage workshops. DEFCAD is one source for these designs.

At least one enterprising individual produced the upper receiver for an AR-15 on a 3-D printer, using acrylonitrile butadiene styrene (ABS) plastic. A YouTube video shows the printed receiver in action. It disintegrated after firing six rounds.

My bet is that the tech will get better, and within a couple of years it will be possible to make a durable metal part on a 3-D printer.

So, should we be worried that every gangbanger will be able to print his own full-auto pistol in his garage?

I doubt it.

When consumer-grade color printers became available, there was a concern that some people would use them for counterfeiting. Some did, of course, and they were mostly discovered and apprehended quickly. CD and DVD burners made it possible to mass-produce copyrighted music and video disks for sale on the street or at swap meets, but those are pretty easy to identify, too.

Some people will, no doubt, try to make illegal firearms and firearm parts with 3-D printers, but I don’t think they will find as large a market for them as is feared. The technology makes it easy to make such things, but making them well is much harder.

Still, if you ever come across a 3-D printer capable of working with metal compounds, you’ll know of one possible use for it.

About the author

Tim Dees is a writer, editor, trainer, and former law enforcement officer. After 15 years as a police officer with the Reno Police Department and elsewhere in Northern Nevada, Tim taught criminal justice as a full-time professor and instructor at colleges in Wisconsin, West Virginia, Georgia, and Oregon.

He was also a regional training coordinator for the Oregon Dept. of Public Safety Standards & Training, providing in-service training to 65 criminal justice agencies in central and eastern Oregon.

Tim has written more than 300 articles for nearly every national law enforcement publication in the United States, and is the author of The Truth About Cops, published by Hyperink Press. In 2005, Tim became the first editor-in-chief for Officer.com, moving to the same position for LawOfficer.com at the beginning of 2008. He now writes on applications of technology in law enforcement from his home in SE Washington state.

Tim holds a bachelor’s degree in biological science from San José State University, a master’s degree in criminal justice from The University of Alabama, and the Certified Protection Professional credential from ASIS International. He serves on the executive board of the Public Safety Writers Association.